Steam



MFETERS, PHOTO-UYHOGRAPMER, WASHINGTON D C.

JOHN ERICSSON, OF LONDON, ENGLAND.

Speciflcationfof Letters Patent No. 588,.dated`February 1, 1838.

To all whom z'tmag/fconcern: y

Be itv known that I, JOHN ERICSSON, a subjectof theKingdom of Swedemresiding at London, England, have invented a new'` and useful Propeller for the Purpose of Propellingy Steamboats Eifectually NotwithstandingY Any Variationsin Their'Draft of Water, and that the following is a full and `exact' description ofi the construction and operation of the said propeller as invented by me.

This invent-ion which I name. as aboveV consists in two thin broad metallic hoops or short cylinders supportedby spiral arms or spokes andmade to revolve in contrary directions but? at different velocities from each other around a commony center,.such hoops or cylinders being also placed entirely underv the water atv the' stern of" a boat and fur-V nished each with a series vof short spiralV planes or. plates; the plates of each series standing at an. angle, the exact converse of the angle given to those ofthe other series and kept revolving. by the power of'a steam engine whereby a steam.. boat may be propelled effectually notwithstanding any variation in the draft of water.

Description of the drawing N0. 1 hereto atafchccl-Figure 1 represents a longitudinal section of the stern` of-y a steam boat with my improvedl propeller'attached. A and B are two cylinders or broadhoopsrof wrought iron supported by spiral arms orspokes which will be explained hereafter-the hoop A is attached to the axis a aga and the hoop Bto the axis b, Z2, b, which latter axis is made hollow in order to' admitthel former to pass through andwork withinit andfboth thesey axes pass directly through the center of the stern post into the body of the vessel. 1,72, 3, 4, 5 and 9, 10, 11, 12, 13 are thin metallic plates attached byy rivets to thehoops A and B the face of each plate being twisted soas toform a portion of a spiral plane or thread, the exact' formof which will be determined and may beobtained'by forminga cylinder and'coiling'a thread or blade spirally around it on the principle exhibited by the diagram represented in Fig. 2 in which A AA represent a cylinder of equal diameter with the hoops A and B in Fig. 1'. a, a, a, a, e, a, a, a, are eight thin spiral planes or plates of thejsame width as the'plates 1, 2, 3, 4, 5 and 9, 10,11, 12 and 13 in Fig. 1, and coiled around the said cylinder A A A spirally like the thread ofa screw the coilsbeing placed at equal distances from each other and each having such aI fall` or inclination thatit will not have passed once'around the cylinder .until it has advanced along 'itl a dist-ance equal to three times its diameter.

`Now if the said cylinder A A A withA its spiral plates or threads be cut off through the'lines I), E and' F G, the portions of the spiral plates between the said lines and which are here numbered 9, 10, 11, 12 and 13 show the exact forms and positions which the plates represented in Fig. 1 `by corre.- -v

sponding numbers should be made toiassume while the forms and positionsV ofv the plates lar manner by running" the coilsv in. a; cron- 1,2, 3, 4L' and 5, will be determined in'Y a simitrai-y direction around the same cylinder. l

Having thus explained the manner in which the forms and p ositoinsof the spiral plates onthe hoops A and B oughtfto be determined I will now continue thedescription of Fig. 1. c, c, c, c, 0,0', c, c, are narrow hoopsof wrought iron passing around and riveted atV the parts marked D in Fig. 3 to' the spiral plates in order. to secure them more firmly intheir places. E E Eis a strong wrought iron stay (better seen in Fig. 3) firmly bolt'- ed to the stern of the vessel. e, is a brass bearing fixed in the saidgstay E which bearsoy ing carries the outer and enlarged endr of the shaft a, a, d, the other end of the shaft being carried by and working through a stuiing box F attached' to the shaftl b, b, Z ,.which shaft is supported by a strong cast iron framing G andl plumber block g1 C yis astuflingbox ixed'to the stern post to prevent the water from-entering the rvessely around the shaft 5,6, 5,whichshould workfreely Athrough-thestern postand I arel two broad cog wheels working together I being about one fifth larger than H. and

attachedto the shaft o, b, 6,1 andH being attachedto a crankshaft Ii L. ,IVI Mis anotherV crank shaft attached' to the shaft aafd by thecoupling box N. Zand m are "cranks on the shafts L and M supportedA by cast-1 iron frames-'P P'and plumber blocks or'bearings 0.20779 p; Q and R are also cranks on'the shafts-NLM and L L fixed at right angles toy the cranks-Z and m. g vand r are crank pins and S a coupling link by which `they cranks Q, and It` are coupled together. T is al connecting rod and Uis a couplingjlink attached to fthe' cranks Z and mi This lconnecting rodl is to be connected iny the ordil'y ioo nary manner to thepiston rodforbe'amof a Y steam engine the cylinder of whichmay be placed either vertically or horizontally across the vessel. Another connecting rod connected to another engine may be attached to the crank pin g in a similar manner by which a more regular power will be communicated to the cranks Yand shafts fm, M and Z L. It is evident that if motion be communicated to the cranks Z and m the shafts L and M must be turned around in one and the same direction and that therefore the shaft Z), b, b, by means of the unequal cog wheels I and II will move in a contrary direction to the shaft a, a, a, and at a less speed and at the same time the broad hoops A and B with their spiral plates will move in contrary directions and at unequal velocities; it should be stated that when the cylinder A and its plates l, 2, 3, 4; and 5 as viewed from-the vessel revolve to the left the vessel` will be propelled forward and when moved to the right the vessel will be backed. W W is the rudder divided into two parts held together by two strong wrought iron stays V fixed them to the progress of theV vessel.

one on each side having wide loops or bends at o to admit of the free motion of the rudder. broad hoops A with its spiral plates. e e e e are cross stays to give additional strength to the stay E E. X X X are the 3 wrought iron' spiral arms or spokes to the hoop A before alluded to and constructed in manner .here shown in order to prevent the resistance which would otherwise be presented by These arms all meet in the center where they are welded to a boss Y which is afterward bored to receive the shaft a, a, a, upon which it is firmly keyed by the keys a a a. D D D D D D D D are t-he angle pieces which join the several pieces C C C C C C C C of the narrow hoop that supports the spiral plates on the broad hoop. J represents the ordinary water line.

And I, the said JOHN ERICSSON, do hereby declare that the application of my propeller represented in the annexed drawing No. 2 and hereafter described will be highly useful either for ships of war or merchant vessels.

Descrz'pz'on, of the elm/wing No. 2.-Fig. 4f represents a longitudinal section and Fig. 5

the plan of the stern of a vessel with my propeller attached and Fig. 6 is a. section showing the manner in which the requisite' contrary movement is obtained in the said application of my propeller. In order the more clearly to describe the said application I will first describe this last mentioned Fig. 6, but previous to doing I have tostate that similar letters of reference will be used to denote similar parts in all the figures. A is a hollow stem of wrought iron, to which are welded collars Z OZ and broad flat branches or arma a. B is an axle or shaft of steel F ig.3 represents an end view of the.

E by which it becomes evident that if mo#V tion be given to the upright shaft the axles B and C, will move in contrary directions.

Gr, H, are two thin broad'hoops of wrought iron, G being firmly fixed on the axle B and II fixed on the hollow axle C. Each hoop is provided with a series of spiral planes as described in the foregoing description of my improved propeller applicable to steam navigation. g g and 71. t are .the spiral spokes also before describedV but which spokes in addition to their twisting or spiral .form are here curved or bent outward in` order to give roomfor the flat arms t a of the hollow stem. In order to protect the conical wheels as well as diminishing the friction which they would produce in passing through the water a drum P P P of slight metal divided into three parts and pointed toward the ends, ismade to inclose all the gear work `under water, the central part of which drum, being fixed to the arms a a and the pointed ends or caps fixed to the spokes of the propellers slits being made Afor that purpose and a space of about one eighth of an inch leftf between the three parts in order to admit of a free and contrary movement of the propellers. Having thus described Fig. 6, representing the section of my propeller as applied to ships of war or merchant vessels, I will now proceed to describe Fig. 4, showing the manner in which it is attached. K is a bracket of iron (better seen at K K), it is firmly xed to the stern for the purpose of carrying the propeller, by means of the hollow stem A and its collars d cZ the hollow stem being kept in its place by the key Ze which is securedto the bracket K by a slight chain. L is a stay ofwrought iron, to keep the hollow stem A firmly in an upright position; and to receive and communicate the force of the propellers for which purpose it is `attached to the stern post by hinges on each side of the rudder; its form will be better seen at L L, the rudder being made to work between Z, Z andthe fork lVI fitted to receive the hollow stem A, which iskept in by a key m this being secured to the stay by a slight chain as shown in the drawing. N

is a ring or collar around the upper part of the hollow stem A, having a strong loop or eye at n. It is evident that by driving out the keys m la and and pushing down is taken on board be lifted up and kept suspended by the hooked rope at R in the position shown by the dotted lines a" r.

I have now to state that the most advantageous mode of giving motion to the propeller is that of applying a steam engine to the crank F, and I would recommend an engine so arranged as represented in Fig. 5, S S being two high pressure steam cylinders placed horizontally and nearly at right angles, their power to be communicated by the forked connecting rods s s to the crank F.

In cases where the application of steam engines would be objectionable manual force may be applied by means of long winches similar to those used for working ordinary chain pumpsV or by means of a capstan made to give motion to the conical cog wheel T, (marked in redlines, see Fig.4,) such cog wheel to work in or give motion to another conical cog wheel V fixed on the upright shaft, F.

N ow whereas the use of spiral planes acting obliquely against the water and moving in contrary directions for propelling steam boats is not new, I do not claim as my invention the use of such spiral planes or their contrary motion; but

I claim as my invention- 1. The metallic hoops or cylinders andA y the spiral arms or spokes hereinbefore described together with the entire immersion of the propeller by which means I am enabled to employ the whole surface of all the spiral plates at one time and whereby the beneficial result of a great propelling force will be obtained by a propeller of much less dimensions than heretofore.

2. And I also claim as my invention the giving a greater speed to the outer series of spiral plates which move in `'the ,current produced by the motion of the other series and by which greater speed the beneficial result of saving of power and increased propelling force'will be obtained.

3. And I further claim as my invention the application of the propeller as described in drawing No. 2-that is to say: lstly, I claim the upright hollow stem with its arms or branches for carrying the propeller by means of which stem the propeller may be either suspended and immersed under the water when required to be used, or on other occasions lifted out of the water so as not to interfere with the sailing of the vessel; Qndly, I claim the drum or conical casing for protecting the bevel wheels and for diminishing the resistance in passing through the water; Srdly, I claim the attaching the propeller to or detaching it from the engine or other power employed on board the vessel by means of a coupling boX at the upper end of the upright shaft of the bevel wheels.

J. ERICSSON. 

